EP2757636A1 - Heat-retractable protection barrier - Google Patents

Abstract

Protection barrier, comprises a sheet of longitudinal plastic material, the transversal dimension of which is unstable upon heating, and the sheet comprises at least one root-repellent agent and/or insecticide agent so as to form a material barrier against roots and/or insects either living or moving in the ground. Independent claims are also included for: (1) manufacturing (M1) a shrinkable protection barrier, comprising (a) introducing and distributing the root-repellent agent and/or insecticide agent in a homogenous manner within a base plastic material, (b) from the composition thus obtained and melted, manufacturing a film, which is transversely stretched while being heated over the crystalline melting point of the base plastic material, where the melting point is below the decomposition temperature of the root-repellent agent and/or the insecticide agent so as not to destabilize the agent(s), and (c) cooling the film; and (2) a method (M2) of using the tubular envelope formed from the protection barrier to create a sealed junction between a protection film and a protection sleeve, where the film and the sleeve is intended to form a material barrier for a buried or half-buried object against roots and/or insects living or moving in the ground, comprising (a1) making a cut into the protection film in order to pass the protection sleeve, (b1) introducing the sleeve through the cut, while ensuring that one overlap part of the protection film thus protruding from the rest of the protection film at least partially covers the edge of the part of the sleeve having passed through the cut, (c1) introducing the tubular envelope via the free end of the part of the sleeve having passed through the cut, where the tubular envelope is positioned so as to at least partially cover the overlap part and the sleeve, and (d1) heating the tubular envelope so that it tightens around the overlap part of the protection film and the protection sleeve.

Description

The present invention relates to a heat-shrinkable protective barrier for protecting semi-buried or buried objects against roots and insects living or moving in the soil. It also relates to a heat-shrink tubular casing formed from such a protective barrier.

It is known that underground conduits used in building, industry, production, transport and distribution of water and energy are victims of biological degradation that over time may alter or destroy their functionality.

Underground ducts may be understood to mean water supply or drainage pipes of a building or installation as well as pipes intended for the passage of electric, pneumatic or optical cables, as well as drains intended for collection and disposal of groundwater.

It is observed that these conduits buried in the ground, or the joints with which they are provided, are eventually colonized by the roots of plants and various invertebrates living or moving in the soil.

Examples of root-clogged drains are numerous and require heavy and expensive replacement operations.

In addition, termites frequently degrade circulation or water supply pipes in order to draw the liquid necessary for their survival.

However, the treatment in the mass of these conduits is not always possible for physical or chemical reasons.

Similarly, the treatment by incorporation of biocidal substances into the mass of materials constituting liquid lines for food use is, for obvious reasons of toxicity, excluded.

The objective of the present invention is therefore to provide a material protection interposed between the ground and the element to be protected, which is simple and inexpensive, easy to implement and to prevent or minimize the damage caused by them. roots and termites or other insects.

Another object of the present invention is a protection that fully encircles the element to be protected while being easy to position around this element.

For this purpose, the invention relates to a flexible protective barrier for a semi-buried or buried object.

According to the invention, this protective barrier comprises a longitudinal plastic sheet whose transverse dimension is unstable by heat, said sheet comprising at least one anti-root agent and an insecticidal agent so as to form a material barrier against the roots. and insects living or moving in the soil, and this barrier having a multilayer structure, it comprises an outer layer comprising an anti-root agent and an inner layer comprising an insecticidal agent.

This sheet comprises both an anti-root agent and an insecticidal agent so as to effectively protect the buried or semi-buried object.

The term "a longitudinal plastic sheet" means that it is a strip sheet or a sheet in the form of a strip.

• cette barrière est d'un seul tenant,

In different particular embodiments of this protective barrier, each having its particular advantages and susceptible to many possible technical combinations:

• this barrier is in one piece,

• au moins la couche externe est formée à partir d'un ou plusieurs polymères thermo-rétractables ou d'un mélange d'un ou plusieurs polymères thermo-rétractable et d'un ou plusieurs polymères non thermo-rétractables, De préférence, les couches externe et interne présentent une dimension transversale instable à la chaleur.

The term "barrier is in one piece" means that this protective barrier is obtained in one piece and therefore does not result from the assembly of initially distinct elements.

• at least the outer layer is formed from one or more heat-shrinkable polymers or a mixture of one or more heat-shrinkable polymers and one or more non-heat-shrinkable polymers, preferably the outer layers. and internal have a transverse dimension unstable to heat.

Advantageously, said at least one outer layer will comprise from 10% to 50% by weight of at least one heat-shrinkable polymer and from 90% to 50% by weight of at least one non-heat-shrinkable polymer.

Thus, it will be ensured that after retraction of the film, or of the tubular casing formed by assembly of the lateral edges of this film, said at least one outer layer will have the same mechanical properties (tear resistance and / or impact, modulus of elasticity, elongation at break, ...) that a film based solely on non-heat-shrinkable polymer. The preservation of the mechanical properties known for non-heat-shrinkable films for this heat-shrinkable film makes it possible to ensure compliance with the decennial guarantee criteria in the field of building and construction.

By way of illustration only, the heat-shrinkable polymer or polymers will be chosen from the group comprising an ethylene-alkyl (meth) acrylate copolymer, a saturated carboxylic acid ethylene-vinyl ester copolymer, an ethylene-ethylenediamine copolymer, vinyl acetate, vinylydene polyvinyl chloride (PVDC), a fluoropolymer such as perfluoro (ethylene-propylene) polymer (FEP) or perfluoroalkoxy (PFA).

Preferably, the outer layer also comprises at least one ultraviolet (UV) absorber.

Advantageously, the outer layer has a permeability to water vapor less than or equal to 1.5 g / m ² / day.1013.25 hPa, such that the permeability to water vapor is measured under a pressure of 1013 25 hPa on an area of 1 m ² for 24 hours at 25 ° C and 60% relative humidity.

• cette couche externe a de plus une perméabilité à l'oxygène inférieure à 5000 cm³/m²/jour.1013,25 hPa, telle que la perméabilité à la l'oxygène est mesurée sous une pression de 1013,25 hPa sur une surface de 1 m² pendant 24 heures à 25°C et à une humidité relative de 60%,

As a purely illustrative example, the non-heat-shrinkable polymer (s) of the outer layer are then selected from the group comprising polyethylene, polypropylene, crosslinked copolymer of ethylene and vinyl acetate, and ethylene-alcohol copolymer. vinyl and polybutene.

• this outer layer also has an oxygen permeability of less than 5000 cm ³ / m ² / day 1013.25 hPa, such that the permeability to oxygen is measured under a pressure of 1013.25 hPa on a surface of 1 m ² for 24 hours at 25 ° C and at a relative humidity of 60%,

An example of a polyolefin-based polymer having both a lower permeability than the aforementioned water vapor and a lower permeability than the oxygen mentioned above is polyethylene. More generally, the inner layer filled with anti-termite insecticide is reinforced by filming of its active surface coming into contact with the ground with the aid of an outer layer of polymer forming a barrier tight to the pH conditions of the medium likely to to cause the degradation of the active ingredient insecticide.

Alternatively, this barrier also comprises an intermediate layer, this intermediate layer having an oxygen permeability of less than 5000 cm ³ / m ² / day ¹⁰ 13.25 hPa, such that the permeability to oxygen is measured under a pressure of 1013.25 hPa on a surface of 1 m ² for 24 hours at 25 ° C. and at a relative humidity of 60%,

• cette couche externe a une épaisseur comprise entre 10 et 150 µm, et encore mieux entre 50 et 100 µm, de manière à limiter la surface de dégradation de la couche externe causée par des insectes avant leur contact avec l'agent insecticide de ladite couche interne,
• les couches interne et externe sont obtenues avec des résines à base de polyoléfines distinctes,
• cette feuille comprend au moins un additif choisi dans le groupe comprenant un agent glissant, un agent antistatique, un agent anti-bloquant, un colorant, un pigment et des combinaisons de ces éléments,
• l'agent anti-racine est un dérivé chlorophénoxy,

An example of a polyolefin-based polymer having a permeability lower than the oxygen mentioned above is polyethylene.

• this outer layer has a thickness of between 10 and 150 μm, and better still between 50 and 100 μm, so as to limit the surface of degradation of the outer layer caused by insects before their contact with the insecticidal agent of said inner layer ,
• the inner and outer layers are obtained with resins based on different polyolefins,
• this sheet comprises at least one additive selected from the group comprising a slip agent, an antistatic agent, an antiblocking agent, a dye, a pigment and combinations of these elements,
• the anti-root agent is a chlorophenoxy derivative,

For example, this anti-root agent is 2- (4-chloro-2-methylphenoxy) propionic acid, also called MCPP acid.

It should be noted that this anti-root agent is a chemical substance with non-pesticidal and non-biocidal properties. The anti-root agent has no lethal effect on roots and trees / plants.

The anti-root effect is a contact effect. The tips of the roots after contact with the barrier lignify, that is to say that the growth of these roots is first slowed down and then stopped. In no case does the tree or plant die because the other memory-based roots unfold in more favorable areas. The preservation of the plant or the tree is thus advantageously ensured.

• ledit insecticide est choisi dans la famille des pyréthrinoïdes, néonicotinoïdes ou carbamates.

The anti-root agent is therefore an anti-root agent with a contact effect.

• said insecticide is selected from the family of pyrethroids, neonicotinoids or carbamates.

By way of illustration, this insecticide may be chosen from the group comprising bifenthrin, alpha-cypermethrin, cypermethrin and permethrin.

The invention further relates to a heat-shrinkable sheath for protecting a pipe or pipe. According to the invention, this sheath is constituted by a protective barrier as described above.

This heat-shrinkable sheath is then formed by assembling the lateral edges of the longitudinal sheet.

This sheath is particularly suitable for clasping pipes, bundles of electrical conduits to be buried to ensure their protection.

Since this sheath is reported, it can advantageously be used to protect pipes carrying water intended for consumption without endangering the end consumer.

Advantageously, when the pipe to be protected acts as a drain, this sheath is micro-perforated to allow a flow of liquids.

The present invention also relates to a method of manufacturing a heat-shrinkable protective barrier as described above.

1. a) on introduit et on repartie de manière homogène au moins un agent anti-racine et/ou agent insecticide dans une matière plastique de base,
2. b) on fabrique à partir de la composition ainsi obtenue et fondue, une feuille en bande que l'on étire transversalement tandis qu'on la chauffe au-dessus du point de fusion cristalline de la matière plastique de base, ce point de fusion étant en dessous du point de décomposition dudit agent anti-racine et/ou dudit agent insecticide de manière à ne pas déstabiliser ledit ou lesdits agents,
3. c) on refroidit ladite feuille en bande ainsi obtenue.

According to the invention, the following steps are carried out:

1. a) at least one anti-root agent and / or insecticidal agent is homogeneously introduced and distributed into a basic plastic,
2. b) a strip sheet which is stretched transversely while being heated above the crystalline melting point of the base plastic is made from the composition thus obtained and melted, this melting point being below the decomposition point of said anti-root agent and / or said insecticidal agent so as not to destabilize said agent (s),
3. c) cooling said strip sheet thus obtained.

Preferably, before cooling said sheet, said sheet is shaped tube or substantially tubular. This forms a tube or a heat-shrink tubular casing.

Advantageously, in step a), said at least one anti-root agent and / or insecticidal agent is introduced into said basic plastic to a temperature between 150 ° C and 200 ° C, and more specifically between 170 ° C and 200 ° C in the case of LDPE.

Preferably, from 10% to 50% by weight of at least one 90% heat-shrinkable polymer to 50% by weight of non-heat-shrinkable polymer is mixed to form said base plastic.

The non-heat-shrinkable polyolefin (s) may be chosen from the group comprising polyethylene (PE), polypropylene (PP), an ethylene-propylene copolymer (EPR), polybutene (PB), polymethylpentene (PMP), ethylene-vinyl acetate (EVA) and polyamide (PA).

By way of illustration, the heat-shrinkable polymer or polymers will be chosen from the group comprising an ethylene-alkyl (meth) acrylate copolymer, a copolymer of ethylene and of a saturated carboxylic acid vinyl ester, an ethylene-acetate copolymer. vinyl fluoride, a polyvinylidene chloride (PVDC), a fluoropolymer such as perfluoro (ethylene-propylene) polymer (FEP) or perfluoroalkoxy (PFA).

Advantageously, at least one slip agent may be incorporated into the melted composition, prior to the preparation of the sheet by extrusion. This slip agent is incorporated so as to be present in the outermost layers of the sheet. Such a slip agent may for example be chosen from fatty acid amides such as erucamide and may be introduced at a rate of 200 to 5000 ppm.

In general, such a slip agent is incorporated into the sheet if it is not intended to be printed. This sliding agent makes it possible to reduce the friction resulting from contact between the heat-shrinkable protective barrier and another surface made of plastic or other material.

By way of illustration, this sliding agent will facilitate the positioning of the heat-shrink tubular casing with respect to a pipe or a package of electrical sheaths to be protected. It is known that by trying to slide a tube on very large cables, these cables become difficult to introduce into the opposite end of the tube.

At least one anti-blocking agent may also be incorporated into the melt prior to extrusion of the sheet. This anti-blocking agent is incorporated so as to be present in the outermost layers of the sheet. This anti-blocking agent serves to reduce the tendency of the sheet to adhere to itself when wound in a coil, so as to facilitate its unfolding.

Such an antiblocking agent generally comprises inorganic filler particles such as silica.

Prior to its use, it is possible to give the sheet antistatic properties. These antistatic properties allow the sheet to remain flat and slide well on the machines, without tending to wind on itself, which could disrupt or block the entire manufacturing process.

For example, the antistatic properties can be made to the sheet by coating its outer layers with a solution of an antistatic agent. Antistatic agents of the alkylamine family are known.

The invention finally relates to the use of the tubular casing formed from said protective barrier as described above or obtained by the manufacturing method as described above, to ensure the tight connection of a protective film and of a protective sleeve, said film and said sleeve being intended to form a material barrier of an object buried or semi-buried against the roots and / or living insects or moving in the ground.

1. a) on réalise une découpe dans ledit film de protection pour permettre le passage dudit manchon de protection,
2. b) on introduit ledit manchon au travers de ladite découpe en s'assurant qu'une partie de recouvrement dudit film de protection formant alors saillie du reste dudit film de protection recouvre au moins partiellement le pourtour de la partie dudit manchon ayant passé au travers de ladite découpe,
3. c) on introduit par l'extrémité libre de ladite partie dudit manchon ayant passé au travers de ladite découpe, ladite enveloppe tubulaire et on positionne ladite enveloppe tubulaire de sorte qu'elle recouvre au moins partiellement ladite partie de recouvrement et ledit manchon,
4. d) on chauffe ladite enveloppe tubulaire de sorte qu'elle enserre ladite partie de recouvrement dudit film de protection et ledit manchon de protection.

According to the invention, the following steps are carried out:

1. a) cutting is made in said protective film to allow the passage of said protective sleeve,
2. b) introducing said sleeve through said cut by ensuring that a covering portion of said protective film then protruding from the remainder of said protective film at least partially covers the periphery of the part of said sleeve having passed through. said cut,
3. c) is introduced through the free end of said portion of said sleeve having passed through said cut, said tubular casing and said tubular casing is positioned so that it covers at least partially said lap portion and said sleeve,
4. d) heating said tubular casing so that it encloses said cover portion of said protective film and said protective sleeve.

Of course, the protective film and the protective sleeve each comprise less an anti-root agent and / or insecticidal agent. We thus obtains a material barrier forming an integral screen to the roots and / or termites, this barrier comprising a flat or substantially plane film and a sleeve forming a main axis chimney out of the plane of this film, this chimney allowing the passage for example electrical ducts.

Preferably, having made in step a) a cross-section of said protective film, it is ensured in step b) that all the free portions of said film resulting from this cutting and integral with said film, surround the part of said sleeve having passed through said cut. These free portions then form the covering portion of said protective film.

Advantageously, in step d), a uniform temperature is applied to all of said tubular casing to avoid the appearance of a local break point in said casing.

The term "homogeneous" means that this temperature applied to the surface of the tubular casing does not vary by more than 20 ° C over the entire surface.

The invention will be described in more detail with reference to the single appended drawing, which schematically shows a heat-shrinkable protective envelope according to a preferred embodiment of the invention;

The single figure shows a heat-shrinkable envelope, or heat-shrinkable sheath, for the protection 1 of electrical sheaths according to a preferred embodiment of the invention.

This protective sheath 1 which is in one piece, can be obtained in particular by multilayer extrusion blow molding.

This protective sheath 1 comprises an outer layer 2 and an inner layer 3. The inner layer 3 is intended to be placed on the side of the electrical sheaths to be protected while the outer layer 2 is intended to be in contact with the ground.

The outer layer 2 comprises an anti-root agent and the inner layer 3 comprises an insecticide. The outer layer 2 advantageously protects the inner layer 3 with anti-termite property.

Indeed, over time, roots can develop in the immediate environment of the protective sheath 1. However, during their growth, these roots could pierce the layer comprising insecticide 3 if it was not protected by the outer layer 2 comprising the anti-root agent. This layer comprising the insecticide lacking or not systemic action, is indeed not phytotoxic. By walking in the root network that they have invested, the termites could then cross without gene a sheath only with an insecticide, this sheath having been previously penetrated at multiple points by the roots.

Furthermore, the outer layer 2 advantageously forms a screen preventing the migration of the insecticide contained in the inner layer 3 to the external environment surrounding the protective sheath 1. Likewise, the interposition of an outer layer 2 between the medium surrounding outer sheath and the inner layer 3 containing the anti termite active prevents the environmental conditions to the sheath do degrade the anti termite active, rendering it ineffective. The properties of the anti termite active are thus preserved over time.

The anti-root active ingredient of the outer layer 2 is, for example, 2- (4-chloro-2-methylphenoxy) propionic acid (CAS No. 93-65-2) incorporated into the mass of the polymer constituting the layer external. 2- (4-Chloro-2-methylphenoxy) propionic acid (CAS No. 93-65-2), for example at doses varying from 0.10% to 2.00% (m / m), has a strong anti-inflammatory effect. -root. Alternatively, this anti-root active may be a chlorophenoxylated herbicide.

The outer layer 2 is obtained from a base plastic comprising 20% by weight of heat-shrinkable polymer and 80% by weight of non-heat-shrinkable polymer. The non-heat-shrinkable polymer is a low density polyethylene (LDPE) while the heat shrinkable polymer is an ethylene-vinyl acetate copolymer (EVA). Advantageously, this copolymer contains from 4% to 30% by weight of vinyl acetate.

The exposure of the heat-shrinkable envelope to a temperature equal to or greater than the softening temperature of the heat-shrinkable polymer causes a retraction of the entire structure of the envelope which then engages the electrical sheaths to be protected. The heat source used to heat the envelope may be a heat gun or a torch.

However, the applied temperature is lower than the decomposition temperature of the anti-root and insecticide agents to avoid destabilizing these agents, which could render them inoperative.

This outer layer 2 also comprises ultraviolet absorber active agents known to those skilled in the art, such as carbon black, salicylates, phenyl benzoates and benzophenones, for example.

This outer layer 2 may represent from 10 to 80% of the total thickness of the protective sheath 1.

In their explorations of the medium, the target insects come into contact with the outer layer 2 which does not repel them. Attempting to cross it, they erode the outer layer 2 and reach a small surface at the inner layer 3 whose insecticide content has not decreased in contact with the external environment surrounding the envelope 1, quickly generates a high mortality on the target insects. The breaks in the outer layer 2 under the action of termites are of a surface too small for the external environment surrounding the envelope 1 can degrade the insecticide.

The inner layer 3 has, for example, a thickness of between 10 microns and 300 microns. This inner layer 3 which comes into contact with the electrical sheaths to be protected constitutes the termite barrier itself. It contains an insecticide of the pyrethroid family integrated in high dose in the mass of the polymer constituting the inner layer.

Bifenthrin (CAS # 82657-04-3) at doses ranging from 0.05% to 2.00% (w / w) in a low density polyethylene layer is suitable without being exclusive. Alpha-cypermetrin permethrin, cypermethrin associated with a polymer selected from the group consisting of low density polyethylene, high density polyethylene, polypropylene and ethylene vinyl acetate are also suitable.

At the stated doses, the insecticide exerts a rapid and lethal action against termites which prohibits any crossing of the protective envelope 1. This inner layer 3 can represent from 20 to 90% of the total thickness of the protective envelope.

The total thickness of the material consisting of the two layers described is likely to vary from 50 microns to 5 millimeters depending on the nature and arrangement of the element to be protected.

Claims (13)

Protective barrier for a semi-buried or buried object, characterized in that said barrier comprises a longitudinal plastic sheet whose transverse dimension is unstable by heat, said sheet comprising at least one anti-root agent and an insecticidal agent so as to form a material barrier against roots and living insects or moving in the ground, and in that said barrier having a multilayer structure, it comprises an outer layer (2) comprising an anti-root agent and an inner layer (3) comprising an insecticidal agent. Barrier according to Claim 1, characterized in that it is in one piece. Barrier according to claim 1 or 2, characterized in that said outer layer (2) further comprises at least one ultraviolet absorber. Barrier according to any one of claims 1 to 3, characterized in that the outer layer (2) has a water vapor permeability less than or equal to 1.5 g / m ² /day.1013.25 hPa, such that the water vapor permeability is measured at a pressure of 1013.25 hPa on an area of 1 m ² for 24 hours at 25 ° C and a relative humidity of 60%. Barrier according to any one of claims 1 to 4, characterized in that said outer layer also has an oxygen permeability of less than 5000 cm ³ / m ² / day.1013.25 hPa, such that the permeability to the oxygen is measured at a pressure of 1013.25 hPa on an area of 1 m ² for 24 hours at 25 ° C and a relative humidity of 60%. Barrier according to any one of claims 1 to 4, characterized in that said barrier further comprises an intermediate layer, said intermediate layer having an oxygen permeability of less than 5000 cm ³ / m ² / day.1013.25 hPa , such that the permeability to oxygen is measured at a pressure of 1013.25 hPa on a surface of 1 m ² for 24 hours at 25 ° C and a relative humidity of 60%. Barrier according to any one of claims 1 to 6 characterized in that at least said outer layer is formed from a or a plurality of heat-shrinkable polymers or a blend of one or more heat-shrinkable polymers and one or more non-heat-shrinkable polymers. Barrier according to Claim 7, characterized in that the heat-shrinkable polymer or polymers are chosen from the group comprising an ethylene-alkyl (meth) acrylate copolymer, a copolymer of ethylene and of a saturated carboxylic acid vinyl ester. an ethylene-vinyl acetate copolymer, a vinylydene polyvinyl chloride (PVDC), a fluoropolymer such as perfluoro (ethylene-propylene) polymer (FEP) or perfluoroalkoxy (PFA). Barrier according to any one of claims 1 to 8, characterized in that said outer layer has a thickness between 10 and 150 microns, and more preferably between 50 and 100 microns, so as to limit the degradation surface of the outer layer caused by insects before contact with the insecticidal agent of said inner layer. Barrier according to any one of claims 1 to 9, characterized in that said sheet comprises at least one additive selected from the group comprising a slip agent, an antistatic agent, an anti-blocking agent, a dye, a pigment and combinations of these elements. Use of the tubular casing formed from said protective barrier according to any one of claims 1 to 10 for sealingly sealing a protective film and a protective sleeve, said film and said sleeve being intended to forming a material barrier of an object buried or semi-buried against the roots and / or insects living or moving in the soil, characterized in that the following steps are carried out: a) cutting is made in said protective film to allow the passage of said protective sleeve, b) introducing said sleeve through said cut by ensuring that a covering portion of said protective film then protruding from the remainder of said protective film at least partially covers the periphery of the part of said sleeve having passed through. said cut, c) is introduced through the free end of said portion of said sleeve having passed through said cut, said tubular casing and said tubular casing is positioned so that it covers at least partially said lap portion and said sleeve, d) heating said tubular casing so that it encloses said cover portion of said protective film and said protective sleeve. Use according to claim 11, characterized in that having made in step a) a cross-section of said protective film, it is ensured in step b) that all the free portions of said film resulting from this cut and secured to said film, surround the portion of said sleeve having passed through said cut. Use according to claim 11 or 12, characterized in that in step d), a homogeneous temperature is applied to all of said tubular casing to avoid the appearance of a local break point in said casing.

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